Display screen technology has advanced over the last few decades, with CRT (cathode ray tube) displays being superseded by LCDs (liquid crystal displays), amongst others, allowing the thickness of televisions and computer monitors to be significantly reduced, giving rise to ‘flat screens’. Flat screens often contain rare earth elements (lanthanides) for their luminescent properties. More recently, the average display size of electronic screens has increased substantially, with modern computer monitors around 30 inches (76 cm) across and modern televisions around 55 inches (140 cm) across.
However, the increased affordability of large electronic screens has contributed to an increased amount of obsolete electronic screens as waste. If not re-purposed, these often end up in landfill because they can be difficult to recycle. At the same time, lanthanides are becoming increasingly expensive and difficult to obtain due to limited mineral resources, meaning that very large electronic screens will be too expensive for most consumers in the near term.
One alternative to a large electronic display is a CAVE (Cave Automatic Virtual Environment)—a type of immersive virtual reality environment used for viewing 3D images. A typical CAVE is a room-sized cuboid, constructed within a larger room, with projectors situated outside the walls of the CAVE to project images onto those walls via rear projection. This mitigates the problem of shadows being cast on the walls by a person moving close to the CAVE walls. Multiple people can use a CAVE at the same time. Bespoke 3D glasses must be worn in order to experience the images as 3D.
However, CAVEs have not been widely adopted for several reasons. First, a large amount of space is required outside a CAVE in order to properly set up its projectors, and most consumers do not have a room of sufficient size at home to accommodate this. A CAVE is also difficult to assemble due to the numerous projectors, screens and cables (which are often a trip-hazard), and is not designed for quick set-up or removal. In other words, a room generally has to be purposefully designated for the use of a CAVE, rather than temporarily accommodating one. Furthermore, expensive custom software is needed to operate a CAVE, and the fact that the images are projected from the exterior of the walls results in reduced image contrast and clarity.